(a) Field of the Invention
The present invention relates to a system and a method of controlling a motor for reducing vibration of an electric vehicle. More particularly, the present invention relates to a system and a method of controlling a motor for reducing vibration of an electric vehicle that maximizes an output torque of the motor by applying a vibration reduction torque gain based on a position value of the accelerator pedal.
(b) Description of the Related Art
Generally, environmentally-friendly vehicles such as an electric vehicle, a fuel cell vehicle, and a hybrid electric vehicle are operated by a driving motor which generates torque using electrical energy. The electric vehicle uses power of the driving motor operated by power of a battery. The hybrid electric vehicle uses power of an internal combustion engine and power of the driving motor. The electric vehicles using the driving motor do not have a damping element between the motor and a driving shaft, thus causing vibration to be generated by the torque of the motor. In the electric vehicle, since the damping element is omitted, vibration such as shock and jerk as well as vibration of a driving shaft occur during shifting and tip-in/out (e.g., operation of pressing or separating accelerator pedal, that is, engaging and disengaging the accelerator pedal) occur which results in deterioration of ride comfort and drivability.
Accordingly, the electric vehicle including the driving motor may use a vibration reduction (anti-jerk) logic to reduce vibration of the vehicle. The vibration reduction logic recognizes a deviation (difference) between model speed and actual speed of the motor as vibration, and multiples the deviation between the two speeds by a predetermined value to obtain a result, and feedbacks the result to suppress the vibration. In other words, vibration is reduced by applying a positive torque or a negative torque based on a currently generated torque according to vibration of the motor. However, when the vibration reduction logic is applied even though a driver requests a maximum torque of the motor, an output torque of the motor adding the negative torque is less than the maximum torque of the motor. Thus, power performance of the vehicle may be deteriorated.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.